Electromagnetically-controlled device



Feb. 9 1926.

J. EATON ELECTROMAGNETICALLY CONTROLLED DEVICE Filed Sept. 29 J ,3 Figl.

Patented Feb. 9, 1926. 1,572,7Q23,

UNITED STATES PATENE FFlCEt JOHN EATON, OF SCHENECTADY, NEW YGRI I,ASESIGNUR T9 ELECTRIC COM- PANY, A CGRFGRATiGN F HAW YORK.

ELECTROMAGEETIQALLY-GOEIZROLLED DEVECE.

Application filed September 539, 1921. Serial No. 504,051.

minimnm valne, and arranged so that he: the energization of theel-ectromngnet above a predetermined maximum Value, the con rolledmember is directly operated away from the second position.

A further object of the invention is to proviee an electromagneticallycontrolled etnrn to the open position.

switch in which a switch member is mag- For a better miderstanding ofthe invennctically held in the closed position against 'tion, referenceis had to the accompanying its bias to the open position when theendrawing in which I have shown one form ergization of the switchelectromagnet is of an improved switch in accordance with 80 above apredetermined value and w ich is he invention for l e purpose ofillustrating magnetically and directly operated to the the principles ofthe inventioi. Referring T 0 aZZ 107mm it may 009100771: the switch. Theelectromagnet is p Be it known that I, JOHN Enron, a snhwitl n movablemeans nn ject of the King of Great Britain, esiding at Schenectady, inthe county of v i arrangement is 5 tady, State of New Yoh, have eticell;

certain new and useful Improve ling IQlectromagnetically-ControlledDevices 'cnit which the following is a specifcati nal m1 One of theobjects of the in; 10 provide an electron'iagnetically device in which acontrolled ineinbei his to one position is magnetically helc secondposition when the eiegization oi the clectromaognet is above a)redetermined open 70 :ce with its bias; or in rload in the controlled 71110?; bl means is mag;-

y o1 al'ed LO open the switch and the swi ch menioer to automaticallyopen position when the energization of the to the drawing; Fig. 1 isaside view 01? my elcctromagnet is above a predetermined nnproved swtehin the oxen position; log.

3.0 nammun value is an end view of the same; Fig. is a A further objecof the invention is to (if p its of the switch in the r t provide acircuit cont oller which combines c osi inn 4' is a detail the featureor manual ontrol and also the ositions oi the parts when ti e c ifeature of automatic c itrsl to protect a ierated to the controlled cirnit from abi-or such, for example, an ovci ore of volt although in caraspects, the invention is not 1' limited to manually conttolled swit 40In carrying the invention into effect in r se :oll(

the switch thei.

ositions one form as applied to an electric swit h, sl 1 to ti ,4:-itions means is provided for closing and openli g s l hen i he manualopening" circuit has n opened automatically in response U, an

c 1 i. the controlled circuit at the will of the o e ator or in responseto any predeternnne c ndition. The sad means may take the on 5 is nsimplilien motor conform of open and close stirt and stop t'i'el d5 sinin which my switch is shown push lnittons, although the ii'ivention isnot co \Ll lOLi and Fig. (3 is a detail shownecessarily limited to apush button operi in view of the magnetic movable ated switch, nor arecertain of the feat ires t' "he controlling electroinegnet and L m 1 loswitch member secured thereto.

59 oi the invention limited in their use to a the movali manuallyoperated switch. A switch mcm- Referring to the dravings, the switch heris nndei' the control of th said mean member 10 is adapted to makeengagement and also under the control or" an electron'iagwith thestationary contact 11 to complete net which may have a single windingeneran elcctric'circnit through the contacts and 55 gized responsivelyto the current through to also energize'the coil 12 of theelectroniagnet for the switch. The movable contact 10 is carried by themovable magnetic member of the elcctromagnet. In the present form 01 myinvention, this magnetic member comprises two relatively movablearmatures 13 and 1 1, the switch member 10 being meehanically connectedto the armature 13 so as to be directly operated thereby. These twoarmatures 13 and 1% are pivotally connected to each other at 15, and thearmature 1 1 is pivotally connected with the frame 16 at 17. The twoarmatures are biased to their respective positions as shown .in Fig. 1by the spring 13, and the arrangement is such that the switch may bemanually closed as shown in Fig. 3 by the opera tion of the close orstart push button 15). After having been closed in this manner, thearrangement is such that the switch will be magnetically held in theclosed position as long as the current in the winding 12 is above apredetermined minimum value, and in case the current in the windingrises to a predetermined maximum value, the armaturc 13 is attractedthereby directly opening the switch and permitting the armatures and theswitch member 10 to return to their respective positions shown inFig. 1. In case the start button 19 is held closed and the current inthe magnet winding is above the predetermined maximum value, thearmature 13 will be attracted to open the switch. When the switch isthus opened it is permitted to automatically reclose. This feature maybe used to advantage in starting an electric motor, the start buttonbeing held closed until the motor accelerates to such a value that theautomatic opening of the switch would not occur during starting and thestart button may then be released so as to provide for automatic voltagefailure and overload protection.

With the switch magnetically held closed as shown in Fig. 3, depressingthe push button 20 causes the switch member 10 to breal; engagement withthe stationary coin tact 11 and thereby open the contact. Releasing thepressure on the push button 20 will permit the armatures and switchmember to return to their respective positions as shown in Fig. 1.

It w'll be observed that the magnetic movable member, comprising thearmatures 13 and 14, is disposed with respect to the magnetic structureof the switch so as to provide an air gap indicated at 21 which may betermed the closing air gap, and another air gap 22 in series with theair gap 21 which may be termed the opening air gap. These two air gapsare in the flux path of the electromagnet and the air gap 21 is closedwhen the switch is closed and mag netically held closed, and the air gap22 is open while the switch is closed. The switch is automaticallyopened when the current in 'the winding 12 rises above a predeterminedmaximum value by the magnetic pull across the air gap 22 against theaction of the spring 18, which provides a resilient connection betweenthe armatures 13 and 14; whereby these armatures are normally biased totheir respective open positions as shown in Fig. 1.

The operation of my invention as thus constructed and arranged may bereadily understood from a consideration of Fig. 5 in connection withFigs. 1, 3 and i. In order to close the switch and thereby energize theel 'JillC motor 23, the start push button 19 will be depressed, therebymoving the armature 141: against the action of the spring 18 to theposition shown in Fig. 3. The pivotal connection between these twoarmatures is located at such a place that the lowering ot the armature11 also lowers the right hand end oi? the armature 13, thereby carryingthe switch member 10 into engagement with the stationary contact 11, asshown in Fig. \Vhen the switch contacts are thus closed, the winding 12of the switch is energized through the switch contacts and the motor 23is connected across the source of supply 24. The armature 1 1 will bemagnetically held in the closed position by the attraction of theelectromagnet for the armature li. In case at any time the voltage oithe supply circuit 24: should either fail or in some other manner thecurrent through the winding be reduced to a predetermined minimum value,the armature 1a is automatically released to return to its normally openposition, thereby simultaneously raising the right hand end of: thearmature 13 and the switch member 10. The circuit for the electric motoris thereby interrupted and will not be completed until the operator doesa definite act, namely depressing the push button 19.

With the switch in the closed position, in case at any time the currenttaken by the electric motor should exceed a predetermined maximum value,the left hand end oi. the armature 13 will be attracted to close the airgap 22 and thereby directly raise the right hand end of the switchmember 10 out of engagement with the stationary contact 11. The circuitthrough the winding 1.2 being thereupon interrupted, the armatures andswitch member are returned to their respective positions as shown in 1by the action of the spring 18. If the operator desires at any time tomanually open the switch, he may do so by depressing the push button 20,thereby causing tie armatures and switch member to a. me theirrespective positions shown in lug. Releasing the push button 20 villpermit the armatures and switch member to return to their respectivepositions shown in Fig. 1.. li both the start and stop push buttons aredepressed while the switch is in the open position, the switch member 10will not be permitted to make engagement with the sta tionary contact11, the arrangement being sucn that the switch member will merely bemoved about the pivot 15 without making engagement with the contact 11.

p I would have it understood that while the invention is useful as acombined manual and automatic overload and voltage failure protectiveswitch, the invention is not necessarily imited to a manually operatedswitch, since the switch may be closed in any suitable manner, as forinstance. electrcmagnetically closed in response to predeterminedcondition, as will be understood by those skilled in the art.

in accordance with the provisions of the patent statutes, I havedescribed the principle of: operation of my invention, together with theapparatus which ll now consider to represent the best embodimentthereot, but I desire to have it understood that the apparatus shown isonly illustrative and ti at the invention may be carried out by othermeans.

hat I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. An electromagnetically controlled device comprising a movable cont'olled memher, a controlling electromagnet theretor having a magneticstructure, a magnetic movable member connected to the said controlledmember and disposed with respect to the said magnetic structure toprovide an air gap which is normally open, a second magnetic movablemember cooperating witl the said first magnetic movable member anddisposed with respect to the said magnetic structure to provide a secondair gap which is open when the controlled member is in a secondposition, and a resilient connection between the said magnetic movablemembers, whereby the controlled member is iioved to the second positionby the operation of the first of said magnetic members to close thefirst said air gap and magnctically held in the second position when theenergization ot' the said electromagnet is above a predetermined minimumvalue, and the controlled member is operated away from the said secondposition by the operation of said second magnetic member due to themagnetic pull across the said second air gap when the energiaation otthe said electrcmagnet is above a predetermined maximum value.

2. An electric switch comprising a movable switch member biased to oneposition, a controlling electromagnet therefor having magnetic movablemeans for holding the said switch member in the second position, thesaid magnetic means being under the control of the magnetic pull acrossan air gap in the flux path of the said electromagnot when the saidswitch member mag netically held in the second position, and amechanical connection between the said magnetic means and the saidswitch member whereby the said switch member is "irectl opera ed awayfrom the second pos1 ticn toward the first pos on by the move ment otthe magnetic means to close the said air gap when the energization oithe said electromagnet reaches a predetcrmined maximum value.

An clecti c switch comprising switch member based to one posit-ion, anelectromet ically holding the said in a second position when ration ofthe said electromag is aborc a predeteunined minimum value, the saidelectron. not having a magnetic member biased to the unattractedposit-ion which moves to the attracted position undcr the control of thesaid electromagnet when the energizz'ation of the said electronctreaches a predetermined maximum value, and mechanical connectionsbetween the said magnetic member and the said switch member whereby thesaid switch member is operated away from the said second position towardthe first position by the said magnetic member when the energization orthe said electromagnet reaches the s=id predetermined maximum value.

The combination in an electric switch of a switch member movable to andfrom a circuit o ening and a circuit closing position, a magnetstructure, movable magnetic means mechanically connected to aid switchmember to move therewith to and from the said positions and disposedwith respect to said magnet structure to provide an air gap which isclosed by the closing of the switch and a second air gap which is openwhen the s itch is closed, and a winding disposed on said structure "forattract ing the said movable magnetic means and thereby holding the saidswitch member 3 the closed position when the first air gap is closed andthe cner" zation of the said winding is abovea predetermined minimumvalue, and magnetically operating the said switch member to the openposition by the pull of the said magnetic movable means across the saidsecond air when the encrgization of the said electromagnet is aboveprcdetern'iined maximum value.

5. electric switch comprising a movable switch member biased to oneposition, a controlling electromagnct there or comprising a windingei1erg',.d rcsponsivcly to the current in the circuit controlled by theswitch, and magnetic movable means for holding the said switch member ina second position, the said magnetic means I sing under the control oithe magnetic pull across an air gap in the tin path of the saidelectromagnct when the said switch member is sition, a controllingelectromagnet having two independently movable armatures controlledthereby for controlling the said switch member, the first of saidarmatures connected to the said switch member and the second of saidarmatures connected to the first armature and the said switch member,and means whereby the switch is by the independent operation of thesecond armature and the said switch member is netically maintained inthe closed poor ion thereby when the energization the said electromagnetis above predetern'iined minimum value, and the said switch member isoperated to the open position by the subsequent independent operation orout, first armature when the energization of the said electromagnet isabove a pr determined maximum value.

12. An electric switch com arising a switch member movable to and froman operated position, a controlling electromagnet therefor comprising amagnet structure and a winding energized responsively to the cur-- rentthrough the switch for mag-notice holding the switch member the operatedposition when the current in the said winding is above a predeterminedminimum value, a magnetic movable member con nected to the switch memberand disposed with respect to the said magnetic structure to provide anair gap, a second magnetic movable member cooperating therewith anddisposed with respect to the said magnetic structure to provide a secondair gap, and a resilient connection between the said magnetic members,whereby the switch member is moved to the operated position by theoperation or" one of said magnetic members to close its correspondingair gap the switch member is returned to its original position by theoperation of the secono magnetic member due to the magnetic pull acrossthe second air gap when the current in the said winding is above a miXimum predetermined value.

18. An electric switch comprising a switch member movable to and from anoperated position, a controlling electromagnet therefor comprising amagnet structure and a winding energized responsively to the cur rentthrough the. switch for magnetically holding the switch member in theoperated position when the current in the said winding is above apredetermined minimum value, a magnetic movable member con nected to theswitch member, a second magnetic movable member, the said magneticmembers disposed with respect to the said magnet structure to providetwo air gaps in series, and a resilient connection between the saidmagnetic members, whereby the switch is closed by the closing of the airg associated with the second magnetic mcmoer and the switch is opened bythe closi k of the air gap ciated with the first magnetic member whenthe current in the said winding is abov a predetermined value.

14-. An electric swi ch comprising a switch member movable to and froman operated position, a controlling electromagnet there for comprisingmagnet structure and a winding energized responsively to the currentthrough the switch for magnetically holding the switch in the operatedposition when the current in the said winding is above predeterminedminimum value, two

movable members pivotally connected to each other a d operativelyconnectel to the said switch member, and a esn'ent connection betweenthe said mag ietic members for biasing the switch to the open positionat which the magnetic members are disposed with respect to the saidu'isgnet strucyre to provide two air gaps in series, whereby the switchis closed by the air gap associated with one of the said magneticmembers and the switch is opened by the closing of the gap associatedwith the other magnetic member when the current in the said winding isabove a predetermined value.

15. The combination in a voltage failure and overload protective pushbutton switch, of a switch member, a controlling electromagnet thereforhaving a single winding and two operatively connected magnetic movablemembers for controlling the said switch member, a push button cooprating with the first of said magnetic members for closing the switchand a push button cooperating with the second of said magnetic membersfor opening the same, and resilient means connecting the said magneticmembers for biasing the said magnetic members and the said switch memberto the ogen position, whereby the switch member is held in the closedposition by the magnetic attraction of the ciectromagnet for the firstof said magnetic members when the current in the said winding is above apredeterminel minimum value and the switch member is returned to theopen position by the maynetic attraction of the elcctromagnet for thesecond of said magnetic members when the current in the said vinding isabove a predetermined maximum value.

In witness whereof, I have hereunto set my hand this 28th day ofSeptember, 1%21.

JOHN EATON.

